The AWIPS MODIS 6.7 micrometer “water vapor channel” image (above) depicts an excellent example of a mountain wave signature over parts of the southern and central Rocky Mountains region, as strong winds associated with a jet stream axis were interacting with the rugged terrain. Note that the corresponding MODIS visible image reveals that very few clouds were present across much of the area where the mountain waves were evident (southern Colorado and northern New Mexico). Aircraft occasionally experience moderate to severe turbulence when they encounter mountain waves — in this case, there were numerous pilot reports of turbulence (below), which included this report in the Denver area at 19,000 feet: